CLASS I. 1. 4. 3. OF IRRITATION. 41 



perhaps sometimes for the purpose of diffusing a part of it over 

 the dry membranes of the fauces and pharynx; in the same 

 manner as tears are diffused over the cornea of the eye by the act 

 of nictitation to clean or moisten it. 



3. Respiratio et Tussis irritativa. In the acts of respiration 

 and of coughing there is an increased motion of the air-cells of 

 the lungs owing to some stimulating cause, as described above in 

 Class I. 1.2. 8. and I. 1.3. 4. and which are frequently per- 

 formed without our attention or consciousness, and are then irri- 

 tative actions; and thus differ from those described in Class II. 

 1. 1.2. and 5. To these increased actions of the air-cells are 

 superadded those of the intercostal muscles and diaphragm by 

 irritative association. When any unnatural stimulus acts so vio- 

 lently on the organs of respiration as to induce pain; the senso- 

 rial power of sensation becomes added to that of irritation, and 

 inflammation of the membranes of them is a general consequence. 



4. Exclusio bills. The exclusion of the bile from the gall-blad- 

 der, and its derivation into the duodenum, is an irritative action 

 in consequence of the stimulus of the aliment on the extremity 

 of the biliary duct, which terminates in the intestine. The in- 

 creased secretion of tears is occasioned in a similar manner by any 

 stimulating material in the eyes; which affects the excretory 

 ducts of the lachrymal glands. A pain of the external membrane 

 of the eye sometimes attends any unusual stimulus of it, then the 

 sensorial power of sensation becomes added to that of irritation-, 

 and a superficial inflammation is induced. 



5. Dentitio. Toothing. The pain of toothing often begins 

 much earlier than is suspected; and is liable to produce convul- 

 sions; which are sometimes relieved, when the gum swells, and 

 becomes inflamed; at other times a diarrhoea supervenes, which 

 is generally esteemed a favourable circumstance, and seems to 

 prevent the convulsions by supplying another means of relieving 

 the pain of dentition by irritative exertion; and a consequent 

 temporary exhaustion of sensorial power. See Class I. 1. 2. 5. 

 Sect XXXV. 3.1. 



The convulsions from toothing generally commence long be- 

 fore the appearance of the teeth; but as the two middle incisors 

 of the lower jaw generally appear first, and then those of the 

 upper, it is advisable to lance the gums over these longitudinally 

 in respect to the jaw-bones, and quite down to the periosteum, 

 and through it. 



As the convulsions attending the commencement of toothing are 

 not only dangerous to life in their greatest degree, but are liable to 

 induce stupor or insensibility by their continuance even in a less 

 degree, the most efficacious means should be used to cure them* 



VOL. II, -G 



